[PATCH 4.19 09/40] ovl: fix value of i_ino for lower hardlink corner case
From: Greg Kroah-Hartman
Date: Mon Apr 20 2020 - 08:48:41 EST
From: Amir Goldstein <amir73il@xxxxxxxxx>
commit 300b124fcf6ad2cd99a7b721e0f096785e0a3134 upstream.
Commit 6dde1e42f497 ("ovl: make i_ino consistent with st_ino in more
cases"), relaxed the condition nfs_export=on in order to set the value of
i_ino to xino map of real ino.
Specifically, it also relaxed the pre-condition that index=on for
consistent i_ino. This opened the corner case of lower hardlink in
ovl_get_inode(), which calls ovl_fill_inode() with ino=0 and then
ovl_init_inode() is called to set i_ino to lower real ino without the xino
mapping.
Pass the correct values of ino;fsid in this case to ovl_fill_inode(), so it
can initialize i_ino correctly.
Fixes: 6dde1e42f497 ("ovl: make i_ino consistent with st_ino in more ...")
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/overlayfs/inode.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -884,7 +884,7 @@ struct inode *ovl_get_inode(struct super
struct dentry *lowerdentry = lowerpath ? lowerpath->dentry : NULL;
bool bylower = ovl_hash_bylower(sb, upperdentry, lowerdentry,
oip->index);
- int fsid = bylower ? oip->lowerpath->layer->fsid : 0;
+ int fsid = bylower ? lowerpath->layer->fsid : 0;
bool is_dir, metacopy = false;
unsigned long ino = 0;
int err = oip->newinode ? -EEXIST : -ENOMEM;
@@ -934,6 +934,8 @@ struct inode *ovl_get_inode(struct super
err = -ENOMEM;
goto out_err;
}
+ ino = realinode->i_ino;
+ fsid = lowerpath->layer->fsid;
}
ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino, fsid);
ovl_inode_init(inode, upperdentry, lowerdentry, oip->lowerdata);